Self-feed carburetor



Aug. 13, 1940. s. M. UDALE SELF FEED CARBURETOR Filed Aug. 15, 193s Patented Aug. 13, 1940'k UNITED STATES SELF-FEED CARBURETOR .Stanley M. Udale, Detroit, Mich.,Y assignor to George'M. Holley and Earl Holley Application August 15, 19-38, Serial No. 224,958

Z Claims.

The object of this invention is to provide an automatic self-lift carburetor in which the suction in the carburetor will increase as the resistance to fuel increases, that is to say, as the grade increases.

In the drawing, A is the-fuel tankhaving an outlet B connected through a pipe C with the diaphragm chamber D. In the entrance to this diaphragm chamber is locted a check valve K. Fuel ows out past a metering pin J ,and through a passage Z into the throat of a small venturi L which discharges on the atmospheric side, but against the downstream lip of a throttle valve H. The throttle lever Q is connected through a link G with a link F connected to the diaphragm D and metering pi-n J. F and G thus form a oneway connection between the throttle H and diaphragm E A spring I provides the operating force for the diaphragm E of the diaphragm chamber D. Hence, when the throttle is closed, the spring I is compressed and when the throttle opened quickly, the spring I moves the diaphragm E at a slower rate than the rate 'at which the throttle is opened.

vAn air valve M is located in the air entrance leading to the throttle H. This air valve is connected by a lever V and by a link W to a diaphragm N located in the fuel entrance C. 'I'his diaphragm N thus acts as a dash pot for controlling the movement of the valve M and it also increases the closing moment on the valve M when the car is climbing a hill.

Additional closing means comprising the weight O may be used to supplement the closing moment of the diaphragm N on the air valve M. The throttle valve H may be provided with an opening S in the center opposite the outlet from the small venturi L to facilitate low speed operation. As vapor will form in the diaphgram chamber D. means must be provided and a passage R causes vapor to beconsumed gradually without disturbing the now of fuel through the passage Z through which the main volume of fuel ows.

The elect of vapor in chamber D is to cut down the ow of fuel in hot weather and may reduce fuel consumption as much as ve per cent,

but this is an incidental result and not the mainobject of the opening R.

Operation The swinging air valve M maintains a suction pressure acting on the 'diaphragm N, together with the weight of the gasoline, causes lthe air valve to close more tightly and thus give a larger lift in the venturi L. The increased inclination also -increases the'eiectiveness of the weight O.

Additionalsuction is created in the small venturi L responsive to the suction in the pipe C. This additional suction is sufficient to create at all times the necessary suction in the throat of the small venturi L. The intention is that the suction created by the weight of the air valve M will' overcome the average friction in the pipe C and the necessary additional lift will be regulated by the suction of the gasoline acting on the dia` phragm N, which additional lift will increase with the grade. Hence the mixture ratio will be independent of the grade.

What I claim is:

1. A oatless self-feed carburetor adapted to obtain its fuel from a fuel tank located beneath said carburetor through an intermediate fuel supply chamber, an'air entrance, an eccentrically pivoted airvalve located therein inherently adapted to be opened by the pressure of the atmosphere, yieldable means for closing said air valve, a mixture chamber on the engine side of said air valve,

a primary venturi communicating with said air entrance and discharging into said mixture chamber,.fuel openings in the throat of said venturi, a passage connecting said fuel openings 'vith said fuel supply chamber, a movable valve forming a variable restriction in said fuel passage, a throttle in the mixture outlet, mechanical connecting means interconnecting the valve con'- trolling the variable restriction` with said throttle, the negative 'head of fuel at said fuel restriction vbeing that -corresponding to the height of said fuel restriction above the level of the fuel'in said fuel supply tank, a movable wall'in said passage subject to slightly lessbut substantially thesame negative head, and" a mechanical connection from said wall to said air valve to apply thereto an additional closing force..

2. A device as set forth in claim l in which there is an additional movable wall in said fuel consists of a one way mechanical connection for closing the restriction by means of the said valve and spring means for moving the connection on opening the throttle and in which there is a nonreturn valve in the fuel passage between the first 5 and second movable walls.

. STANLEY M. UDALE. 

